Rock bit



Aug. 4, 1936. J. c. WRIGHT ET AL 2,049,531

ROCK BIT Filed July 27, 1954 2 Sheets-Sheet l fNVE/VTGPS fa-sac- CI h Rlfih'T JOHN hf HOWARD A 7' TORNEY Aug. 4, 1936. J. c. WRIGHT ET AL- ROCK BIT Filed July 27, 1934 2 Sheets-Sheet 2 lm z/vrms 123.16 C. MIGHT Jhw hf flown/ea v 4 MM/ A TTO'QNEY Patented Aug. 4, 1936 noon arr Jesse C. Wright, Los Angeles, and John H. Howard, Huntington Park, Calif., minors to Globe Oil Tools Company, Los Nietos, Calif., a corporation of California Application July 27, 1934, Serial No. 737,252

9 Claims.

This invention relates to a well drilling bit and relates more particularly to a cone type rock bit. A general object of the present invention is to provide a practical. effective and improved rock bit embodying a simple, one piece head and two or more substantially conical cutters rotatably supported on the lower endof the head for efficient operation and in relatively close proximity to one another.

Another object of the invention is to provide a simple practical and effective means for rotatably mounting or supporting the roller cutters of a rock bit.

Another object of the invention is to provide an improved means for rotatably supporting a substantially conical cutter of a rock bit that is such that the cutter may be readily removed from the head and replaced withoutinterference from and without disturbing the other cutter or 29 cutters oi the bit. In accordance with the present invention any one of the roller cutters of the bit may be attached to and removed from the head by moving it in a plane substantially parallel with the inner side of one of the legs of the head, without moving it past the center of the head and without requiring the separation of any of the parts of the body or head.

' Another object of the invention is to provide a dependable means for rotatablymounting or supporting a roller cutter of a rock bit that carries the cutter for free rotation in an eillcient cutting position without the danger or possibility of loss or displacement.

Another object of the invention is to provide a rock bit having means for rotatably mounting or supporting a cutter that presents or provides large continuous bearing surfaces that are efiective and long wearing.

Another object of the invention is to provide a rock drill or bit comprising a shank or head, an improved part or assembly carrying a roller cutter for rotation and a dependable releasable tongue and groove connection between the cutter supporting part or assembly and the head.

A further object of the invention is to provide a rock bit of the character mentioned in which the parts of the tongue and groove connection between the head and the cutter carrying parts is such that its members are tightly locked against relative movement so that they cannot become worn and may be employed to mount new or replacement cutters.

Other objects and features of the invention will be better and more fully undestood from the following detailed description of typical forms and applications of the invention, throughout which description reference may be had to the accompanying drawings, in which:

Fig. 1 is a side elevation of a drill embodying the present invention showing one quarter in 5 longitudinal cross section. Fig. 2 is a fragmentary detailed sectional view taken substantially as indicated by line 2-4 on Fig. 1. Fig. 3 is an end view, of a cutter and its support or mounting showing the lock key in operative posil0 tion. Fig. 4 is a sectional view of the lock nut of the bearing assembly. Fig. 5 is a sectional view of the connecting plate embodying the tongue. Fig. 6 is a sectional view of the wear taking washer of the bearing assembly. Fig. 7 15 is a sectional view of the cutter retaining ring. Fig. 8 is a longitudinal sectional view of the cutter carrying bearing pin. Fig. 9 is a longitudinal sectional view of one of the cutters removed from the other parts. Fig. 10 is a longitudinal detailed 20 sectional view of a cutter and a modified or alternative form of bearing part. Fig. 11 is a longitudinal detailed sectional view of a three cutter bit embodying the present invention. Fig. 12 is a bottom elevation of the bit illustrated in Fig. 11 25 and Fig. 13 is a bottom elevation of the bit head illustrated in Fig. 11 with two of the cutter assemblies removed and illustrating a portion of the assembly in cross section, as indicated by the line l3-l3 on Fig. 11. 30

The embodiment of the present invention illustrated in Figs. 1 to 9, inclusive, of the drawings, includes, generally, a shank or bit head l0, cutters ll, bearing assemblies l2 rotatably carrying or supporting the cutters II, and means i3 35 detachably or removably connecting the bearing assemblies I 2 with the bit head l0.

The shank or head i0 is adapted to be connected to the lower end of a well drilling string of drill pipe or the like. In accordance with the 40 broader principles of the invention the head l0 may be varied considerably in shape and construction, it being a feature of the invention that the head i0 may be of one piece or integral construction, as illustrated throughout the drawings. 45 The upper portion ll of the head ill may be cylindrical and may be provided with suitable means for connecting with the drilling string. In the case illustrated in the drawings a tapered screw threaded pin l5 projects from the upper 50.

end of the portion M to facilitate the connection of the head with the string. The lower portion of the shank or head III is enlarged and provided with downwardly projecting legs It to carry the cutters II. In the form of the invention being described there are two cutters II and the head is provided with two legs l6 each carrying a cutter. The legs I! are preferably in diametrical opposition and are equally spaced from the central longitudinal axis of the head. The inner sides I! of the legs I6 are inclined downwardly .and outwardly relative to the central longitudinal axis of the 'bit. The outer sides or surfaces of the legs l3 ,may be curved or otherwise shaped and may be joined at their lower ends by the inclined inner sides IT. A central longitudinal fluid passage I Oextends downwardly through .the head from the upper end of the pin ii to discharge downwardly between the'legs IS. A discharge jet or been I3 of reduced diameter is provided in the lower portion of the opening l8 to increase the velocity of the discharging circulation fluid.

The cutters l I are conical or substantially conical it being understood that the cutters embodied in the invention may be frustro-conical or of other configurations. The exteriors or outer surfaces of the cutters l i are provided with cutting parts. The particular cutters ll illustrated in the drawings have circumferential rows or series of teeth 20. The teeth are suitably spaced and sharpened to axially extending edges. The bases 2| of the cutters II are flat and substantially normal to the longitudinal axes of the cutters. Central bores or sockets 22 enter the cutters ll from-their bases 2|. The sockets 22 terminate within the cutters and their inner end walls 23 may be tapered or conical. A counterbore or cylindrical concentric recess 24 is provided in the base 2| of each cutter.v

The bearing assemblies l2 for rotatably supporting or carrying the cutters ll include shafts or hearing pins 25 extending into and cooperating with the sockets 22 of the cutters. The bearing pins 25 have bearing or supporting engagement with the walls of the openings 22 and may have conical ends 26 to cooperate with the conical ends of the sockets during the assembling of the parts, as will be more fully described. The bearing pins 23 are shouldered between their ends having reduced portions 21 and axially facing shoulders.

In accordance with the invention an annular groove 23 of substantially semi-circular cross section is provided in the wall of each socket 22. Y

The axially facing shoulders of the bearing pins 23 have seats 23 of partially circular cross section to register withor oppose the grooves 28. A retaining ring or lock ring 33 which is normally of less than 360 is passed into each socket 22 around the bearing pin 21 and is forced or sprung into the groove 28 in the interior of the cutter. The bearing pins 25 are proportioned so that they may be moved to the bottoms of the sockets 22 in which position their seats 23 are spaced inwardly from the recesses 23 to allow the lock rings 33 to be arranged in the grooves 28. The lock rings 33 are contracted to some extent when passed into the sockets 22 so that they automatically expand or spring outwardly into the grooves 23.

Wear taking bushings or washers 3| are arranged on the reduced portions 21 of the pins to extend into the sockets 22 and cooperate with the lock rings 34. Seats 32 of partially circular cross section are provided on the inner ends of the washers 3| to bear against the lock rings 30. The washers 3| have flanges 33 which occupy or cooperate with the recesses 24 in the bases of the cutters. The flanges 33 have bearing cooperation with the cylindrical walls of the re- 'the rotatable cutters H.

Cylindrical recesses 34 are provided in the outer sides of the washers 33 and the bearing pins 25 are provided with reduced threaded stems 35 which project outwardly through the recesses 34. Plates 36 are threaded on the stems 35 and are received in the recesses 34 to clamp against their bottom walls. Dowels 31 cooperate with openings in the flanges 33 and plates 36 to lock the plates and washers against relative tuming. Lock nuts 38 may be threaded and welded on to the stems 35 to lock the parts of the assembly against displacement. Clamping of the threaded plates 36 against the washers 3| locks the parts in the positions where the seats 23 and 32 both have proper cooperation with the lock rings 33 to hold the cutters ll against longitudinal movement on the bearing pins 25. Therings 30 positively prevent outward or downward displacement of the cutters from the'pins.

The means l3 for detachably connecting the cutter carrying bearing assemblies l2 with the head l0 are in the nature of tongue and groove connections. In the preferred construction dovetailed tongues 40 are provided on the outer sides of the plates 36. The tongues 43 are diametrical with respect to the longitudinal axis of the bearing assemblies and are comparatively heavy. The longitudinal sides of the tongues 43 diverge outwardly from the outer sides of the plates 36. Dove-tailed recesses or grooves 4| are provided in the inner sides I! of the legs It to receive the tongues 40. It is a feature of the invention that the grooves 4| extend from exposed surfaces of the legs so that the tongues 43 may be readily insorted in them. In'the construction being described the grooves 4| extend upwardly and inwardly from the lower ends of the legs l6 whereby the tongues 43 may be introduced or started in the lower ends of the grooves and the cutters II and their bearing assemblies moved in a plane parallel with the surfaces IT to their proper positions on the bit head. The grooves 4| terminate at their upper ends in abrupt shoulders 42. The upper or inner ends 43 of the tongues 40 are adapted to bear against the shoulders 42. When a cutter II and its bearing parts have been assembled the tongue 40 of the bearing assembly may be started in one of the grooves 4| and the assembly moved upwardly and inwardly to bring the tongue to a position where its upper end 43 bears on the shoulder 42. It is to be particularly noted that this positioning of the cutter assembly on the head I0 is done without moving the cutter assembly past the vertical center of the head and without requiring the separation of any body or head parts. I

The means l3 may embody a structure or arrangement for taking up looseness in the tongue and groove connections and for tightly and accurately fitting the tongues 40 in the grooves. A tapered shim or key 44 may be arranged between a tapered side of each tongue 40 and one wall of the groove receiving the tongue. The sides of the tongues 43 engaged by the keys 44 are preferably inclined or pitched longitudinally as clearly illustrated in Fig. 13 or the drawings. The keys 44 arranged between the walls of the grooves 4| and the inclined sides of the tongues 40 lock the tongues against lateral movement in the grooves.

Means are provided for releasably or detachably locking the tongues 48 in the grooves 4|. Transverse openings 46 are provided in the legs it to intersect thegrooves 4| at points above the longitudinal axes of the cutter and bearing assemblies. The openings 46 are clearly illustrated in Fig. 13. Notches or slots 41 are provided in the tongues 48 to register with the openings 46. The

openings 46 and slots 48'are preferably rectangu lar in transverse cross section. Tapered keys 48 are passed or driven through the openings 46 and slots 41 to wedge or urge the tongues upwardly in the grooves so that their upper ends 43 bear against the shoulders 42. The tapered keys 48 positively prevent detachment of the bearing assemblies from the head l8.

It is believed that the manner of assembling the cutters II and bearing assemblies i2 will be apparent from the foregoing detailed description. When the tongues 48 are passed upwardly in the grooves 4|, the outer sides of the plates 36 and flanges 33 slidably bear against the inner sides ll of the legs. When the tongues 48 are in their final positions against the shoulders 42 the outer sides of the plates 36 and flanges 33 have extensive engagement with the inner sides of the. legs. The upward thrusts or end thrusts from the rotatable cutters II are received by the flanges 33 which have extensive direct engagement with the inner sides of the legs l6. The assembly of the bearing pins 25 and washers 3| have larger cylindrical bearing surfaces rotatably carrying the cutters The peripheries of the flanges 33 present effective bearing surfaces for rotatably cooperating with the cylindrical walls of the recesses 24 to aid in rotatably carrying the cutters. The cutter retaining rings 38 have engagement with the grooves 28 throughout substantially the entire circumferential extents of the sockets 22 so that the cutters are evenly supported.

is rotated in the usual manner and the engagement of the cutters I with the rock or earth formation results in reverse direction of the cutters with respect to the head. The cutters II are rotatably supported in positions to project downwardly and outwardly from the lower ends of the legs l6 and have effective cutting or crushing engagement with the earth formation. The cutters rotate about downwardly and inwardly inclined axes so that their lower peripheral portions or teeth 22 engage the formation at the bottom of the bore substantially in a common plane. The opposing sides or parts of the cutters II are accordingly substantially vertical and the circulation fluid discharged from the bean l8 passes between the cutters to effectively flush their cutting parts.

When it becomes desirable or necessary to replace the cutters the keys 48 may be driven from the openings 46, whereupon the tongues 40 may be moved through the grooves 4| to discon' nect the bearing assemblies |2 from the bit head. The nuts 38 and plates .36 are unthreaded from the bearing pins 25 to permit the separation of the cutters from their bearing pins. When the new or replacement cutters have been assembled on their bearing pins 25 the bearing assemblies may again be connected to the head ||I by the means l3. It may be desirable to replace the tongues are locked in place by the keys 48. The

washer 32 .when the cutters are replaced. However, the plates 36 are tightly and securely retained on the head 10 and receive little or no wear so that they do not require replacement; In replacing or re-applying the cutter assemblies to 5 the head they are moved upwardly and inwardly in planes substantially parallel with the inner sides of the legs until the upper ends 43 of the tongues engage the shoulders 42, whereupon the cutter assemblies may be easily and quickly attached to and removed from the head without interfering with one another and without necessitating the disconnection or separation of parts of the head.

Fig. 10 of the drawings illustrates a modified or alternative bearing means for carrying a cutter II for rotation. In this construction an integral bearing 25 is employed instead of the bearing assembly of the pin 25, washer 32 and plate 36. The bearing is received in the socket 22 of the cutter and has an annular groove 58 of substantially semi-circular c oss section to oppose or register with the groove 8. An opening 5| in the cutter communicates with the registering 25 grooves. A lock key is driven or forced through the opening 5| into the registering grooves 28 and 58 to lock the rotatable cutter against longitudinal displacement from the bearing. The bearing 25 has a base flange 33*- for 30 cooperating with the walls of the recess 24. A tongue is provided on the projecting outer end of the flange 33 to fit one of the grooves 4| of the head. It is believed that it will be apparent how the bearing 25 carrying the cutter 3 may be readily attached to the head ID by means l3.

Figs. 11, 12 and 13 of the drawings illustrate I the invention embodied in a well drill or bit having three roller cutters i of substantially coni- .m

cal configuration. The shank or. head Ill is formed to carry the three roller cutters being provided with three downwardly projecting legs I6. The inner sides of the legs are preferably flat and are inclined downwardly and outwardly. The inner sides N of the legs are of equal or uniform extent and join at radial inclined lines X to bound an opening or recess in the bottom of the head of truncated pyramidal configuration. A longitudinal passage l8 extends through the 5 head Ill and has a bean I9 at its lower end discharging downwardly into the upper end of the opening or recess just mentioned. Dovetailed grooves 4| are provided in the walls or sides II of the legs and extend upwardly from the lower ends of the legs. The grooves 4| receive the tongues 40 on the plates 36 of the bearing assemblies. The cutters H and the bearing assemblies |2 may be the same as described above. Fig. 13 of the drawings clearly illustrates the manner of removably locking the tongues 40 of the three assemblies in the grooves 4| by means of the keys 48.

Having described only typical preferred forms and applications of our invention, we do not wish to be limited or restricted to the specific forms and applications herein set forth, but wish to reserve to ourselves any modifications or variations that may appear to those skilled in the art or fall within the scope of the following claims.

Having described our invention, we claim:

1. In a well bit of the character described, a bearing pin, two elements, one a head, the other a plate removably locked on the bearing pin, one element having a groove, a tongue on 75 the other element cooperating with the groove to connect the plate and pin with the head, releasable means locking the tongue in the groove comprising a tapered lock key passing transversely through the groove and cooperating with the tongue. and a roller cutter rotatably carried by the bearing pin.

2. In a well bit, a head having a downwardly projecting leg, a roller cutter of substantially conical configuration; there being a groove in the inner side of the leg, and means for mounting the cutter on the leg to rotate about an inclined axis including, a bearing pin carrying the cutter for rotation and having an annular groove, a ring cooperating with the groove to retain the cutter on the pin, a bushing on the pin retaining the ring in position, a plate removably locked on the pin, and a tongue on the plate adapted to be passed into the groove to connect the plate and pin with the leg.

3. In a well bit of the character described, a head, a leg on the lower end of the head having a downwardly and outwardly inclined inner side, a substantially conical cutter, a pin rotatably carrying the cutter and having an annular groove, a member in the groove holding the cutter on the pin, a plate removably locked on the pin, a tongue and groove connection between the plate and the inner side of the leg whereby the cutter is rotatable about a downwardly and inwardly inclined.

axis, and a part on the pin retaining the member in the groove and having bearing cooperation with the inner side of the leg.

4. In a well bit of the character described, a head, a leg on the lower end of the headhavin a downwardly and outwardly inclined inner side, a substantially conical cutter, a bearing rotatably carrying the cutter, the bearing including a hearing pin rotatably carrying the cutter, and a washer surrounding the pin and having bearing cooperation with the base of the cutter and the inner side of the leg, a part removably locked on the pin, and a tongue and groove connection between the said part and the leg.

5. In a well bit of the character described, 9.

head, a leg projecting from the lower end of the head, a roller cutter, a bearing pin rotatably carrying the cutter, a part surrounding and removably locked wh the pin, and a tongue and groove' connection between said part and the leg. 5 6. In a well bit of the character described, a head, a leg projecting from the lower end of the head, a roller cutter, a bearing pin rotatably carrying the cutter, means holding the cutter against longitudinal movement on the pin, a part sur- 1 rounding and removably locked on the pin, and a tongue and groove connection between said part and the leg.

7. In a well bit of the character described, a head, a leg projecting from the lower end of the head, a roller cutter, a bearing pin rotatably carrying the cutter, a removable member on the pin having cooperation with the cutter for more than around the pin to hold the cutter against displacement from the pin, a part surrounding and 20 removably locked on the pin, and a tongue and groove connection between said part and the leg.

8. In a well bit of the character described, a head, a leg projecting from the lower end of the head, a roller cutter, a bearing pin rotatably car- 25 rying the cutter, the cutter having an internal groove, a member surrounding the pin and coopcrating with the groove to hold the cutter against displacement from the pin, a bushing on the pin removably retaining the member in position, a 30 plate removably locked on the pin and holding the bushing on the pin, and means removably connecting the plate with the leg.

9. In a well bit, a roller cutter having a socket and a groove in the wall of the socket, a pin extending into the socket to rotatably support the cutter, a ring on the pin cooperating with the recess to hold the cutter against longitudinal displacement from the pin, a bushing on the pin holding the ring in place, and a plate removably locked on the pin and adapted to be connected to the bit body. 3

JESSE C. WRIGHT.

JOHN H. HOWARD. I 

